A sheet metal bending brake, commonly referred to as a brake, typically consists of a flat surface (bottom member) onto which the material (sheet metal) is placed, and a clamping bar which will come down and hold the material firmly during the bending process. This clamping action may be manual, automatic or operated using a foot pedal. The front, gate-like, plate of the machine is hinged and may be lifted, forcing the material extended over a straight edge to bend to follow the plate. The bends may be to any angle up to a typical practical limit of about 120 degrees, somewhat more in the case of a bar folder. If the area to be bent is narrow enough, a sharper bend (e.g., for a hem) can be made by inserting the bend under the clamping bar and lowering it.
The frame of such a brake is typically comprised of an interconnected series of flattened C-shaped members that open frontward and hold the top and bottom members at corresponding top and bottom lips of the C-shape. The flattened C-shaped members being rigidly connected to longitudinal members forming part of the brake frame. Sheet bending brakes of this character are well known, and many are designed to be portable so that they can be transported for use at temporary work sites, typically to be set up on sawhorses or the like. Therefore, such brakes must be rugged, and any accessories must likewise be rugged and also capable of being quickly and easily assembled and disassembled, if the accessories protrude from the main body of the brake, or adapted to meet the requirements of the current sheet metal bending required.
Currently, commercial sheet bending brakes are generally available with lengths from approximately 2 meters (approximately 6.5 feet) to 4.5 meters (approximately 14.5 feet). Typically, an approximately U-shaped handle is provided on top for actuating the clamping/unclamping action of the top member. Similarly, a pair of straight handles, or alternatively U-shaped or other shaped handles, hang downward from the bending member such that an operator can reach down, grasp the handle, and pivotably lift it to bend the clamped sheet material over the bending anvil. Typically, the sheet material is 24″ wide, possibly supplied from a coil or roll, and as a “workpiece” the sheet material extends forward out away from the top and bottom clamping members. The operator, typically a single individual, must align the desired bending line of the sheet material (workpiece) with the bending anvil, and then both support and hold in position the sheet material with one hand while reaching over to close the clamp with their other hand. Then the operator must reach down and pull up the bending member handle, possibly while still supporting the sheet material with one hand. Therefore, a problem associated with conventional sheet bending brakes is providing support for the sheet material extending in front of the brake. Particularly for longer pieces of sheet material, an assistant to the operator may be needed, but of course this adds to labor costs.
This issue is exacerbated where, with typical sheet material being 24″ wide, a 1″ bend requires that the flattened C-shaped members of the frame accept 23″ of sheet material. As such, for the brake to accommodate the fullest range of bends then the frame should essentially accommodate 24″ minus the smallest length of the bent section, for example 0.5′. Accordingly, it would be beneficial for the brake frame and flattened C-shaped members to be large enough to support the range of bends desired by the user but have minimum footprint for ease of storage etc.
Another problem associated with conventional sheet bending brakes lies in squaring sheet material with respect to the bending anvil as the sheet material is inserted into the brake. That is, it is generally desired that bends or cuts in the sheet material made with the assistance of the sheet bending brake be square and parallel to an edge of the sheet material and to each other. Making the cuts or bends square to the material edge can be a time-consuming operation, resulting in undesirable expense and scrap. Accordingly, it would be beneficial for the operator to have rapid simple visual assurance that the sheet was square within the bending brake prior to committing to the bend.
Another problem with conventional sheet bending brakes is the labor and expense associated with formation of compound bends (including hems) in the sheet material when forming building trim elements and the like. For example, it is conventional practice to employ a ruler or scale to make marks at the ends of a length of sheet material, and to use these opposed marks in an effort not only to square the sheet material in the bending brake but also to locate the positions of the desired bends or cuts. For compound bends, marks may need to be made on both sides of the sheet. Another conventional technique is to employ a small strip of material, such as scrap material, to form the desired contour or profile of the trim element, including multiple bends and hems as desired. When the strip has been bent to a satisfactory contour, it is then flattened again in such a way that the stresses imparted to the strip material at each bend are plainly visible as marks on the flattened strip, thereby generating a “template strip”. The template strip is then placed in turn along each end of the sheet of material to be contoured and manual cutters or snips are used to mark the longitudinally spaced material ends at lateral positions at which the material sheet is to be bent or cut. After the sheet is bent and cut, the ends having the snip marks usually must be trimmed off. It is self-evident that this is a time-consuming and expensive operation that undesirably increases the costs of building construction. Accordingly, it would be beneficial to provide a means of allowing the brake operator to perform bending operations without marking the sheet material reducing time required per bend but also reducing waste from incorrect measurements. In some instances where the brake user regularly performs similar operations it would be beneficial to provide them with quick visual markers for aligning the sheet metal thereby further reducing required time and waste. It would also be beneficial to provide the user with easily adjustable and accurately settable gauges and other aids or accessories could significantly improve an operator's efficiency in such situations.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.